<template>
  <div class="count">
    <h2>当前求和为: {{sum}}</h2>
    <select v-model="n">
      <option :value="1">1</option>
      <option :value="2">2</option>
      <option :value="3">3</option>
    </select>
    <button @click="add">加</button>
    <button @click="minus">减</button>
  </div>
</template>

<script setup lang="ts" name="Count">
import {ref} from "vue";

let sum = ref(1)
let n = ref(2)

function add() {
  sum.value += n.value
}
function minus() {
  sum.value -= n.value
}

</script>

<style scoped>
  .count {
    background-color: skyblue;
    padding: 10px;
    border-radius: 10px;
    box-shadow: 0 0 10px;
  }
  select, button {
    /* 上下, 左右*/
    margin: 0 5px;
    height: 25px;
  }
</style>